CN103498051B - Method for recovering copper and nickel from nickel-iron-copper alloy waste - Google Patents

Abstract

The invention relates to a method for recovering copper and nickel from nickel-iron-copper alloy waste, and belongs to the technical field of comprehensive utilization of resources. First oxidize and remove iron: raise the temperature of nickel-iron-copper alloy waste to obtain molten nickel-iron-copper alloy waste, then add slagging agent and spray into oxidizing gas to obtain molten metal and slag; then a stage of electrolytic refining to recover copper: use the above steps to obtain The molten metal is cast into a soluble anode, and then the soluble anode plate is used as the anode, the stainless steel plate is used as the cathode, and copper sulfate is used as the electrolyte. After electrolysis, copper can be prepared on the cathode; finally, the second stage of electrolytic refining recovers nickel: the above steps The electrolytic refining electrolyte is heated up to remove iron and copper and then sent to the nickel electrolytic cell as the electrolyte for nickel recovery. The insoluble titanium plate is used as the anode and the stainless steel plate is used as the cathode. Nickel can be prepared on the cathode after electrolysis. The invention effectively integrates the three processes of alloy structure destruction, anode plate casting and iron removal by oxidation, and the process has remarkable energy-saving effect.

Description

A method for recovering copper and nickel from nickel-iron-copper alloy waste

technical field

The invention relates to a method for recovering copper and nickel from nickel-iron-copper alloy waste, and belongs to the technical field of comprehensive utilization of resources.

Background technique

China's nickel supply consists of two parts, one part is the supply of newly produced nickel concentrate, which accounts for 72.9% of the total nickel supply, and the other part comes from secondary nickel, accounting for 27.1%. With the development of economic construction and steel industry, nickel's The demand is constantly increasing. After China's nickel consumption is expected to reach 400,000 tons per year in 2010, China will become the world's largest nickel consumer. In 2010, the basic reserves of nickel metal in China were only about 2.3 million tons. From 2010 to 2013, there was no significant progress in China's nickel ore exploration. If consumption continues like this, China's nickel ore resources will gradually be exhausted in 10 years. Similar to it. To alleviate the resource pressure of my country's copper and nickel resources, it is necessary to increase the utilization efficiency of secondary resources.

At the same time, nickel-copper alloy scraps are increasing year by year, mainly including scraps generated during machining, scraps generated during smelting, and damaged alloy components and parts in industrial sectors. In addition, most of the nickel-copper alloy scraps currently circulating in the domestic market are purchased from Japan, South Korea, and Taiwan, China. They are scraps produced by electronic component factories, and their chemical components are mainly nickel and copper. The resource utilization of nickel will undoubtedly play a more positive role in alleviating the pressure on my country's nickel and copper resources. However, the current utilization method of this alloy scrap is to add it as an alloy element additive in the alloy manufacturing process after classification, and the utilization rate is low and the economic performance is poor.

Contents of the invention

Aiming at the problems and deficiencies of the above-mentioned prior art, the present invention draws lessons from the idea of electrolytic refining of complex copper raw materials, and provides a method for recovering copper and nickel from nickel-iron-copper alloy waste, which adopts remelting oxidation iron removal-two-stage electrolytic refining The method of recovering the nickel and copper in it is the method of breaking the nickel-iron-copper alloy structure by remelting, and recovering the copper and iron in the way of controlling the size of the electrolytic cell and the low voltage of the cell by segmented electrolysis. The invention effectively couples the three processes of alloy structure destruction, anode plate casting and iron removal by oxidation, and the process has a remarkable energy-saving effect, and recovers copper and iron through segmental electrolysis, and the comprehensive utilization of waste resources is high, which has the prospect of industrial promotion and application Well, the present invention is realized through the following technical solutions.

A method for reclaiming copper and nickel from nickel-iron-copper alloy waste, the concrete steps are as follows:

(1) Oxidation and iron removal: first, the nickel-iron-copper alloy scrap is heated to 1500-1650°C to obtain molten nickel-iron-copper alloy scrap, then a slagging agent is added to the molten nickel-iron-copper alloy scrap and oxidizing gas is sprayed to keep After reacting at this temperature for 10-120 minutes, molten metal and slag are obtained;

(2) One-stage electrolytic refining to recover copper: cast the molten metal obtained in step (1) into a soluble anode, then use the soluble anode plate as the anode, the stainless steel plate as the cathode, and copper sulfate as the electrolyte, and the voltage in the cell is 1.6 to 3.0 V. Conduct electrolysis in a copper electrolytic cell with an electrolyte temperature of 45-60°C and a homopolar distance of 60-95mm, and intermittently supplement Cu ²⁺ during the electrolysis process to maintain the Cu ²⁺ ion concentration in the electrolyte at 20-80g /L, copper can be prepared on the cathode after the cathode cycle ends;

(3) The second stage of electrolytic refining to recover nickel: the electrolytic solution after step (2) is heated up to remove iron and copper, and then sent to the nickel electrolytic cell as the electrolyte for nickel recovery. The insoluble titanium plate is used as the anode, and the stainless steel plate As the cathode, electrolysis is carried out in a nickel electrolytic cell with a cell voltage of 2.4-2.8V, an electrolyte temperature of 40-65°C, and a homopolar distance of 80-100 mm. Nickel can be prepared on the cathode after the cathode cycle is completed.

The nickel-iron-copper alloy scrap comprises the following components in mass percentage: 0.5-20% Fe, 60-80% Cu, and 3-20% Ni.

The slagging agent is one of SiO ₂ and blast furnace slag or a mixture of two in any proportion, and the added amount is 0.5 to 2.5 times the mass of iron in the nickel-iron-copper alloy.

The oxidizing gas is air, oxygen-enriched air or oxygen, and the injection pressure is 0.01-0.8 MPa.

In the step (2), the width and height of the copper electrolytic cell are respectively 1.0 to 3.0 times the width and length of the soluble anode.

The Cu ²⁺ added in the step (2) is one of CuSO ₄ and CuCl ₂ or a mixture of the two in any ratio.

The cathodic cycle of the first stage of electrolytic refining and the second stage of electrolytic refining is 7-10 days.

The process of increasing the temperature of the electrolyte to remove iron in the above step (3) is:

First use sodium carbonate to adjust the pH of the electrolyte to about 1.5, then raise the temperature to 90-95°C, use activated carbon as a catalyst, blow in air to oxidize, and react for 3 hours to generate yellow-jarosite and filter to achieve preliminary iron removal; then use sodium carbonate to adjust When the pH reaches about 2.0, use hydrogen peroxide to oxidize Fe ²⁺ into Fe ³⁺ , and then generate jarosite. After filtration, the iron removal rate is over 99%.

The process of removing copper from the electrolyte in the above step (3) is:

The process adopts the sulfidation precipitation method to remove copper. During the process, the pH value of the beginning is controlled between 2.0 and 3.0, and the pH value of the end point is between 3.5 and 4.0, so that copper sulfide can be precipitated and removed.

The above-mentioned homopolar spacing is the distance between anodes and anodes, and between cathodes and cathodes.

The beneficial effects of the invention are: (1) The three processes of alloy structure destruction, anode plate casting and iron removal by oxidation are coupled into one, and the process has a remarkable energy-saving effect; The products are electrolytic copper and electrolytic nickel with high added value; (3) The method is highly universal and can be extended horizontally to the treatment of other alloy wastes with similar structures; (4) The process is simple to operate and the production cost is low.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Detailed ways

The present invention will be further described below in combination with the accompanying drawings and specific embodiments.

Example 1

As shown in Figure 1, the method for reclaiming copper and nickel from nickel-iron-copper alloy waste, its concrete steps are as follows:

(1) Oxidation and iron removal: first, heat up the nickel-iron-copper alloy scrap to 1500°C to obtain molten nickel-iron-copper alloy scrap, then add slagging agent to the molten nickel-iron-copper alloy scrap and spray oxidizing gas to maintain this temperature After reacting for 10 minutes, molten metal and slag were obtained. The nickel-iron-copper alloy waste material included the following components in mass percentage: Fe0.5%, Cu80%, Ni19.5%; the slagging agent was SiO ₂ , and the amount added was 0.5 times the mass; the oxidizing gas is air, and the injection pressure is 0.01MPa;

(2) One-stage electrolytic refining to recover copper: cast the molten metal obtained in step (1) into a soluble anode, then use the soluble anode plate as the anode, the stainless steel plate as the cathode, and copper sulfate as the electrolyte. The voltage in the cell is 1.6V, The electrolysis is carried out in a copper electrolytic cell with an electrolyte temperature of 45°C and a homopolar distance of 60mm, and Cu ²⁺ is supplemented intermittently during the electrolysis process to maintain the Cu ²⁺ ion concentration in the electrolyte at 20g/L. Copper can be prepared on the cathode, wherein the size of the soluble anode is 670×870×10mm, and the width and height of the copper electrolytic cell are 1.0 times the width and length of the soluble anode respectively; the added Cu ²⁺ is CuSO ₄ ; the cathode The cycle is 7 days;

(3) The second stage of electrolytic refining to recover nickel: the electrolytic solution after step (2) is heated up to remove iron and copper, and then sent to the nickel electrolytic cell as the electrolyte for nickel recovery. The insoluble titanium plate is used as the anode, and the stainless steel plate As the cathode, electrolysis is carried out in a nickel electrolytic cell with a cell voltage of 2.4V, an electrolyte temperature of 40°C, and a homopolar distance of 80mm. Nickel can be prepared on the cathode after the cathode cycle is over, and the cathode cycle is 7 days.

The process of increasing the temperature of the electrolyte to remove iron in the above step (3) is:

First use sodium carbonate to adjust the pH of the electrolyte to about 1.5, then raise the temperature to 90°C, use activated carbon as a catalyst, blow in air to oxidize, and react for 3 hours to generate jarosite and filter to achieve preliminary iron removal; then use sodium carbonate to adjust the pH to 2.0 or so, use hydrogen peroxide to oxidize Fe ²⁺ to Fe ³⁺ , and produce yellow sodite. After filtering, the iron removal rate reaches more than 99%.

The process of removing copper from the electrolyte in the above step (3) is:

The process adopts sulfidation precipitation method to remove copper. During the process, the initial pH value is controlled at 2.0 and the final pH value is 3.5, so that copper sulfide can be precipitated and removed.

The copper and nickel obtained by the electrolysis are analyzed and tested, and the purity of copper is 99.91%, and the purity of nickel is 99.993%.

Example 2

As shown in Figure 1, the method for reclaiming copper and nickel from nickel-iron-copper alloy waste, its concrete steps are as follows:

(1) Oxidation and iron removal: firstly, the nickel-iron-copper alloy scrap is heated to 1650°C to obtain molten nickel-iron-copper alloy scrap, then a slagging agent is added to the molten nickel-iron-copper alloy scrap and oxidizing gas is sprayed to maintain the temperature After reacting for 120 minutes, molten metal and slag were obtained, wherein the nickel-iron-copper alloy waste material included the following components in mass percentage: Fe20%, Cu60%, Ni20%; the slagging agent was a mixture of _SiO2 and blast furnace slag with a mass ratio of 1:1, and the amount added was It is 2.5 times the mass of iron in nickel-iron-copper alloy; the oxidizing gas is oxygen-enriched air, and the injection pressure is 0.8MPa;

(2) One-stage electrolytic refining to recover copper: cast the molten metal obtained in step (1) into a soluble anode, then use the soluble anode plate as the anode, the stainless steel plate as the cathode, and copper sulfate as the electrolyte. The voltage in the cell is 3.0V, Electrolysis is carried out in a copper electrolytic cell with an electrolyte temperature of 60°C and a distance between the same poles of 95 mm, and Cu ²⁺ is supplemented intermittently during the electrolysis process to maintain the Cu ²⁺ ion concentration in the electrolyte at 80 g/L. Copper can be prepared on the cathode, where the size of the soluble anode is 700×900×10mm, and the width and height of the copper electrolytic cell are 3.0 times the width and length of the soluble anode, respectively; the added Cu ²⁺ is 1:1 by mass CuSO ₄ and CuCl ₂ mixture; cathode cycle is 10 days;

(3) The second stage of electrolytic refining to recover nickel: the electrolytic solution after step (2) is heated up to remove iron and copper, and then sent to the nickel electrolytic cell as the electrolyte for nickel recovery. The insoluble titanium plate is used as the anode, and the stainless steel plate As the cathode, electrolysis is carried out in a nickel electrolytic cell with a cell voltage of 2.8V, an electrolyte temperature of 65°C, and a homopolar distance of 100mm. Nickel can be prepared on the cathode after the cathode cycle is over, and the cathode cycle is 10 days.

The process of increasing the temperature of the electrolyte to remove iron in the above step (3) is:

First use sodium carbonate to adjust the pH of the electrolyte to about 1.5, then raise the temperature to 95°C, use activated carbon as a catalyst, blow in air to oxidize, and react for 3 hours to generate jarosite and filter to achieve preliminary iron removal; then use sodium carbonate to adjust the pH to 2.0 or so, use hydrogen peroxide to oxidize Fe ²⁺ to Fe ³⁺ , and produce yellow sodite. After filtering, the iron removal rate reaches more than 99%.

The process of removing copper from the electrolyte in the above step (3) is:

The process adopts sulfidation precipitation method to remove copper. During the process, the initial pH value is controlled at 3.0 and the final pH value is 4.0, so that copper sulfide can be precipitated and removed.

The copper and nickel obtained by the electrolysis are analyzed and tested, and the purity of copper is 99.95%, and the purity of nickel is 99.998%.

Example 3

As shown in Figure 1, the method for reclaiming copper and nickel from nickel-iron-copper alloy waste, its concrete steps are as follows:

(1) Oxidation and iron removal: firstly, the nickel-iron-copper alloy scrap is heated to 1600°C to obtain molten nickel-iron-copper alloy scrap, then a slagging agent is added to the molten nickel-iron-copper alloy scrap and oxidizing gas is sprayed to maintain the temperature After reacting for 80 minutes, molten metal and slag were obtained, wherein the nickel-iron-copper alloy waste material included the following components in mass percent: Fe19%, Cu78%, Ni3%; the slagging agent was blast furnace slag, and the amount added was the mass of iron in the nickel-iron-copper alloy 1.5 times; the oxidizing gas is oxygen, and the injection pressure is 0.5MPa;

(2) One-stage electrolytic refining to recover copper: cast the molten metal obtained in step (1) into a soluble anode, then use the soluble anode plate as the anode, the stainless steel plate as the cathode, and copper sulfate as the electrolyte. The voltage in the cell is 2.4V, Electrolysis is carried out in a copper electrolytic cell with an electrolyte temperature of 50°C and a distance between the same poles of 85 mm, and Cu ²⁺ is supplemented intermittently during the electrolysis process to maintain the Cu ²⁺ ion concentration in the electrolyte at 60 g/L. Copper can be prepared on the cathode, where the soluble anode is 720×900×10mm, and the width and height of the copper electrolytic cell are 2.0 times the width and length of the soluble anode respectively; the added Cu ²⁺ is CuCl ₂ ; the cathode cycle for 9 days;

(3) The second stage of electrolytic refining to recover nickel: the electrolytic solution after step (2) is heated up to remove iron and copper, and then sent to the nickel electrolytic cell as the electrolyte for nickel recovery. The insoluble titanium plate is used as the anode, and the stainless steel plate As the cathode, electrolysis is carried out in a nickel electrolytic cell with a cell voltage of 2.6V, an electrolyte temperature of 55°C, and a homopolar distance of 90mm. Nickel can be prepared on the cathode after the cathode cycle is over, and the cathode cycle is 9 days.

The process of increasing the temperature of the electrolyte to remove iron in the above step (3) is:

First use sodium carbonate to adjust the pH of the electrolyte to about 1.5, then raise the temperature to 93°C, use activated carbon as a catalyst, blow in air to oxidize, and react for 3 hours to generate jarosite and filter to achieve preliminary iron removal; then use sodium carbonate to adjust the pH to 2.0 or so, use hydrogen peroxide to oxidize Fe ²⁺ to Fe ³⁺ , and produce yellow sodite. After filtering, the iron removal rate reaches more than 99%.

The process of removing copper from the electrolyte in the above step (3) is:

The process adopts sulfidation precipitation method to remove copper. During the process, the initial pH value is controlled at 2.5 and the final pH value is 3.8, so that copper sulfide can be precipitated and removed.

The copper and nickel obtained by the electrolysis are analyzed and tested, and the purity of copper is 99.93%, and the purity of nickel is 99.997%.

Claims (6)

1. a method for reclaiming copper, nickel from nickel-iron-copper alloy waste, is characterized in that concrete steps are as follows: (1) Oxidation and iron removal: first, the nickel-iron-copper alloy scrap is heated to 1500-1650°C to obtain molten nickel-iron-copper alloy scrap, then a slagging agent is added to the molten nickel-iron-copper alloy scrap and oxidizing gas is sprayed to keep After reacting at this temperature for 10 to 120 minutes, molten metal and slag are obtained; the slagging agent is one or a mixture of two of SiO ₂ and blast furnace slag in any proportion, and the amount added is 0.5 to 2.5 times the mass of iron in the nickel-iron-copper alloy; (2) One-stage electrolytic refining to recover copper: cast the molten metal obtained in step (1) into a soluble anode, then use the soluble anode plate as the anode, the stainless steel plate as the cathode, and copper sulfate as the electrolyte, and the voltage in the cell is 1.6 to 3.0 V. Conduct electrolysis in a copper electrolytic cell with an electrolyte temperature of 45-60°C and a homopolar distance of 60-95mm, and intermittently supplement Cu ²⁺ during the electrolysis process to maintain the Cu ²⁺ ion concentration in the electrolyte at 20-80g /L, copper can be prepared on the cathode after the cathode cycle ends; (3) The second stage of electrolytic refining to recover nickel: the electrolytic solution after step (2) is heated up to remove iron and copper, and then sent to the nickel electrolytic cell as the electrolyte for nickel recovery. The insoluble titanium plate is used as the anode, and the stainless steel plate As the cathode, electrolysis is carried out in a nickel electrolytic cell with a cell voltage of 2.4-2.8V, an electrolyte temperature of 40-65°C, and a homopolar distance of 80-100 mm. Nickel can be prepared on the cathode after the cathode cycle is completed. 2. The method for reclaiming copper and nickel from nickel-iron-copper alloy scrap according to claim 1, characterized in that: the nickel-iron-copper alloy scrap comprises the following components in mass percentage: Fe0.5-20%, Cu60 ~80%, Ni3~20%. 3. The method for recovering copper and nickel from nickel-iron-copper alloy waste according to claim 1 or 2, characterized in that: the oxidizing gas is air, oxygen-enriched air or oxygen, and the injection pressure is 0.01-0.8 MPa . 4. The method for recovering copper and nickel from nickel-iron-copper alloy scrap according to claim 1 or 2, characterized in that the width and height of the copper electrolytic cell in the step (2) are respectively the width and height of the soluble anode 1.0 to 3.0 times the long dimension. 5. The method for recovering copper and nickel from nickel-iron-copper alloy scrap according to claim 1 or 2, characterized in that the Cu ²⁺ added in the step (2) is one of CuSO ₄ and CuCl ₂ One or two mixtures in any proportion. 6. The method for recovering copper and nickel from nickel-iron-copper alloy waste according to claim 1 or 2, characterized in that: the cathodic cycle of the first stage of electrolytic refining and the second stage of electrolytic refining is 7 to 10 days.